Upload
others
View
6
Download
0
Embed Size (px)
Citation preview
ICAO Colloquium on Aviation and Climate ChangeICAO Colloquium on Aviation
and Climate ChangeICAO Colloquium on
Aviation and Climate ChangeICAO Colloquium on
Aviation and Climate Changeand Climate ChangeAviation and Climate ChangeAviation and Climate Change
Application of Liquid Hydrogen as Aviation Fuel
– Some Perspectives– Some Perspectives
Keiichi OKAIKeiichi OKAIJet Engine Technology Research Center,
Aerospace Research and Development Directorate,J A E l i AJapan Aerospace Exploration Agency
ICAO Colloquium on Aviation and Climate Change
Scope of the presentationScope of the presentation
• Introduces study on aero‐engine and relatedIntroduces study on aero engine and related aircraft systems being conducted at JAXA in fundamental research and development basis.
• Introduces expectations to acquire a new sustainable, energy‐efficient and environmentally compatible alternative aviation fuel.
• Deals with the potential of one of the promising fuels – hydrogen‐.
ICAO Colloquium on Aviation and Climate Change
Hydrogen as Aviation fuelHydrogen as Aviation fuelIn comparison with the current jet fuelsM iMerits+ Higher energy content per weight (3 Times)+ Zero (CO2) emission+ Potential for lower NOx emission+ Potential for lower NOx emission+ Easy handling as combustible gasDemerits- Lower energy content per volume (1/4 times)Lower energy content per volume (1/4 times)- Hard handling in storage and supply (cryogenic fuel).- Material property(brittleness)Additional Concerns►Fuel sustainable supply (with environmental compatibility)►Infrastructure (airport)► Impact of water vapor emission (>2 times) on atmosphere
ICAO Colloquium on Aviation and Climate Change
FeasibilityFeasibility
• Several feasibility studies show LH2 subsonic transport y paircraft is realistic, whereas there are still some ambiguities such as fuel storage and fuel supply systems still existsystems still exist.
• Small aircraft (from take off to landing) and cruising phase with medium size aircraft were already demonstrated(-1988).
• Fuel cell powered small aircraft with hydrogen fuel has already been demonstrated already(2008 2009)already been demonstrated already(2008, 2009)
• Realization of Large-scale and long-time duration aircraftRealization of Large scale and long time duration aircraft … still remains a challenge.
ICAO Colloquium on Aviation and Climate Change
Merits of introduction ofMerits of introduction of LH2 to Aviation …
• The aviation industry is ideal to demonstrate a hydrogen y y gfuelled transport society, having experts in restricted areas at airports to supply and manage the fuel.
Aerospace industry is close to hydrogen…• First demonstrated turbojet-engine used for propulsion• First demonstrated turbojet-engine used for propulsion
was hydrogen fueled (He178). • Efforts on development of Model 304 hydrogen-fueled
engine were redirected to the development of the RL10 hydrogen/oxygen rocket engine. We can utilize tremendous experiences of hydrogen-relatedtremendous experiences of hydrogen related technologies for rocket propulsion.
ICAO Colloquium on Aviation and Climate Change
ChallengesChallenges
Major challenges for LH2 fueled (subsonic)Major challenges for LH2 fueled (subsonic) transport are as follows:
(1) Fuel supply management(2) Tank structure (Fuel Storage system)(2) Tank structure (Fuel Storage system)(3) Evaluation of effect of water vapor emission on
environmentenvironment
*Sustainable and stable supply of the fuel is of*Sustainable and stable supply of the fuel is of course a precondition.
ICAO Colloquium on Aviation and Climate Change
Three examples of JAXA investigationinvestigation
Case 1: LH2-fuelled Hypersonic Transport yp p(HST) turbojet engine
Case 2: LH2-fuelled Blended Wing Body (BWB) Configuration Supersonic Transport (SST)
Case 3: Hybrid Aero-Engines
ICAO Colloquium on Aviation and Climate Change
Case 1: LH2 HST turbo‐engineCase 1: LH2 HST turbo‐engine
- Scaled (LH2-fueled) Pre-cooled turbojet engine model operable from SLS to Mach 5 in-flight condition (with single flow-path) has been fabricated and tested.
Experiences obtained in the series of tests on turbojet engine engine systems- Experiences obtained in the series of tests on turbojet engine, engine systems, fuel supply system and fuel tank are also applicable to hydrogen fueled supersonic and subsonic transport.- Investigation includes fuel handling techniques such as fabrication study ofInvestigation includes fuel handling techniques such as fabrication study of cryogenic multiphase flow control and visualization of the flow.
Reference:T hi H H d K K b hi H K ji T H h M M ki D S i S d M Y
Flow visualization Multiphase flow control
-Taguchi, H., Harada, K., Kobayashi, H., Kojima, T., Hongoh, M., Masaki, D., Sawai, S. and Maru, Y., "Firing Test of a Hypersonic Turbojet Engine Installed on a Flight Test Vehicle,“ 16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference, AIAA 2009-7311, 2009. -Shirai, Y., Shiotsu, M., Tatsumoto, H., Kobayashi, H., Naruo, Y., Inatani, Y., Preliminary study on heat transfer characteristics of liquid hydrogen for coolant of HTC Superconductors, Cryogenic Engineering Conference and International Cryogenic Materials Conference, Arizona, USA, June 28 - July 2, 2009
ICAO Colloquium on Aviation and Climate Change
ICAO Colloquium on Aviation and Climate Change
Case 2: LH2-fuelled BWB Configuration SSTCase 2: LH2-fuelled BWB Configuration SST
‐Light weight and BWB configuration ma ha e a meritmay have a merit=> Energy efficient, Low‐emission and Low‐boom large‐size SST
Sonic Boom Intensity
4
ConventionalJet ALarge SST
Sonic Boom Intensity
4
ConventionalJet ALarge SST ConventionalJet ALarge SST
2
3
△P (psf)
Low Boom
C
Concorde
Small SST
LH2/BWBSST
BWB
LH2 fuel
2
3
△P (psf)
Low Boom
C
Concorde
Small SST
LH2/BWBSST
BWB
LH2 fuel
Low Boom
C
Concorde
Small SST
LH2/BWBSST
BWB
LH2 fuel
0
1
0 10000 20000 30000 40000 500001/2
Target : 0.3~0.5 psf
B
0
1
0 10000 20000 30000 40000 500001/2
Target : 0.3~0.5 psf
B
Target : 0.3~0.5 psf
B
W/L1/2 W : lbs L : feetW/L1/2 W : lbs L : feet
Reference: Horinouchi, S., Future Supersonic Transport with Hydrogen Fuel and BWB Configuration, JSASS-2010-1067, presented in the 41th JSASS Annual Meeting, 2010.
ICAO Colloquium on Aviation and Climate Change
Case 3: Hybrid aero-engines (1/2)Case 3: Hybrid aero-engines (1/2)PowerPower‐‐weight weight relationship of electric propulsion system componentsrelationship of electric propulsion system components
NASA: AIAA2003‐2867
With hydrogen as the fuel, fuel cell or fuel-cell and gas-turbine combination (hybrid) engine would have higher efficiency and higher environmental compatibility than sole gas-turbine engine. Reducing weight in related devices is one of the key technological challengesReducing weight in related devices is one of the key technological challenges.In addition to introduction of hydrogen fuel, aspects of More Electric Aircraft (MEA)would be key technologies of future aircraft, and hybrid engine technology should beconsidered as one aspects of MEA.
ICAO Colloquium on Aviation and Climate Change
A new light-weight motor conceptg g pCase3 (2/2)
1.Driving coils (point of action) on
A new motor concept *1
1.Driving coils (point of action) on the outer shell2.No need of iron core(Large current variation; Relax physical limits)
‐> Small (relative) resistance loss
Turbo-fan engine has a limitation in fan-bypass ratio which is an important parameter concerning efficiency and environmental impact (emission and noise).El t ti f t ti ll l thi li it ti b f i d d t t ti d
3.Energy recovery via LC circuitVectored thrust and foldable fans*2Distributed propulsion
Electromagnetic fan may potentially release this limitation, because of independent rotation speed from turbine and its (potential) light weight.
*1 K. Okai, H. Nomura, T. Tagashira and R. Yanagi, Electromagnetic Rotating Machine, US-Patent # 7423405 (2008)*2 K. Okai, H. Nomura, T. Tagashira and R. Yanagi, Aircraft Propulsion System, US-Patent # 7555893 (2009)
ICAO Colloquium on Aviation and Climate Change
SummarySummary
- Hydrogen has long been a “new” promising alternative fuel.Recent activities for hydrogen society is a good background to- Recent activities for hydrogen society is a good background to
accelerate the development of hydrogen fuelled aircraft.- Research on hydrogen fuelled aircraft has been conducted quite a long ti d d t dd t th h fi ldtime, and we need to add some new aspects on the research field regarding the most recent social needs.- Systems verification approach would be promising because storage andh dli f h f l f ihandlings of the fuel are of great issue.- Hydrogen fuelled aviation would become a good demonstration for introduction of hydrogen society because handling of aviation fuel is done by trained persons and in restricted areas.- Introduction of hydrogen as aviation fuel would further encourage the development of fuel cell powered aircraft. Fuel cell or hybrid propulsion should be considered as an activity among the ones for More Electric Aircraft (MEA).